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Finding the Fourth Proportional to 3.12, 4.31 and 2.78

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Solution

The fourth proportional to 3.12, 4.31 and 2.78 is: 3.84

Step by Step Solution

  1. Step 1: Write the proportion equation
    3.12 : 4.31 = 2.78 : x
  2. Step 2: Convert to fraction form
    3.12/4.31 = 2.78/x
  3. Step 3: Cross multiply
    3.12x = 4.31 × 2.78
  4. Step 4: Simplify right side
    3.12x = 11.97
  5. Step 5: Solve for x
    x = 11.97/3.12
  6. Step 6: Final answer
    x = 3.84

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.